1. Field of the Invention
The invention relates to a safety belt device and a seat assembly incorporating the same, more particularly to a safety belt device that is suitable for application to different seat members, that can be automatically restored to an initial state when released from a fastened state, and that can be adjusted to suit different sizes of users to be seated on the seat member.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional car safety seat 1 includes a seat base 11, a seat body 12 disposed on the seat base 11, and a safety belt device 13. The seat body 12 includes a seat portion 121, a pair of lateral portions 122 extending respectively from opposite lateral sides of the seat portion 121, and a backrest portion 123 connected to the seat portion 121 and the lateral portions 122. The safety belt device 13 includes a pair of spring sleeves 131 that are disposed spacedly on the seat portion 121 and that are respectively adjacent to the lateral portions 122, a pair of spring sleeves 132 that are disposed spacedly on the backrest portion 123 and that are respectively adjacent to the lateral portions 122, a pair of shoulder straps 133 each extending between a respective one of the spring sleeves 131 on the seat portion 121 and a respective one of the spring sleeves 132 on the backrest portion 123 and each provided with a buckle tongue 134, and a buckle 135 provided on the seat portion 121 to engage removably the buckle tongues 134.
In an unused state, the spring sleeves 132 on the backrest portion 123 and the spring sleeves 131 on the seat portion 121 extend upward to tauten the shoulder straps 133, as best shown in FIG. 1. When a child (not shown) is seated on the seat portion 121, the shoulder straps 133 can be brought over the shoulders of the child, and the buckle tongues 134 are subsequently fastened to the buckle 135. At this time, the spring sleeves 132 on the backrest portion 123 deform to bend downward and accumulate a restoring force, as best shown in FIG. 2. Thereafter, when the buckle tongues 134 are released from the buckle 135, the spring sleeves 132 release the restoring force accumulated thereby to once again tauten the shoulder straps 133.
However, since the spring sleeves 132 are fixed at one end on the backrest portion 123, the heights of the spring sleeves 132 on the backrest portion 123 cannot be adjusted in order that the shoulder straps 133 can suit different children to be seated on the seat portion 121. Moreover, in view of the fixed mounting design of the safety belt device 13, it cannot be removed for subsequent application to another seat.